Difference between VIN E or K 4.0s

[DaaQ]

Hi all, I have a question on this vin E notation that pops up alot on the Rock Auto site for 2003 Explorers.
After some research, it's the 8th position letter in the VIN to determine engine type.

My particular vehicle has a "K" engine code in the VIN.

Now my particular truck has had the motor replaced once. ( Thank you timing chain/guide/tensioner masterpiece of engineering)

Anyway, what is the main difference between the K and E versions?
Is there another spot with the engine code stamped? Like on the block itself?

Thanks for any info.

 

[swshawaii]

K = Flex Fuel? Sorry, no idea of engine serial number location.
http://www.explorerforum.com/forums/showthread.php?t=387456
http://www.explorerforum.com/forums/showthread.php?t=286772

Maybe?
http://www.explorerforum.com/forums/showpost.php?p=2602611&postcount=5
http://www.explorerforum.com/forums/showthread.php?t=124020

 

[swshawaii]

Also found this pic:

http://www.explorerforum.com/forums/showpost.php?p=2522849&postcount=4

 

[extra-medium]

Vin code e is non flex fuel, code k is flex fuel. To my knowledge the engine is the same, but the fuel system is different to accommodate the more corrosive properties of E85.